Cured prepreg moldings (fiber-reinforced composites) composed of carbon-fiber-reinforced plastics (CFRP), etc. are conventionally produced by curing prepregs with excess margins, and cutting off the excess margins from the resultant cured molding by a cutting tool such as an endmill, a rooter, etc., to secure high dimensional accuracy. However, the fiber-reinforced composites are hard to cut because of high strength and rigidity, resulting in rapid wear of cutting tools and thus short life of cutting tools. Also, fibers extend from the cut surface like fluff, and interlaminar peeling occurs on the cut surface by vibration during cutting, resulting in decrease in strength and fatigue failure. An endmill having fine diamond particles electrodeposited on cutting edges was proposed as that with improved wear resistance, but this endmill fails to have elongated life because of clogging of dust.
As a method of cutting a fiber-reinforced composite member without generating fluff and burr on a cut surface, JP 59-27827 B proposes a method of cutting a fiber-reinforced composite member fixed by a jig with a blade-overlapping portion of a rooter having blades with different helix angles.
As an endmill causing no clogging of dust during the cutting of a fiber-reinforced composite member, JU 2-82461 A proposes an endmill having grinder particles electrodeposited on a grinding surface, and provided with dust-discharging grooves on grinding peripheral surface.
As a method of cutting a fiber-reinforced plastic laminate while preventing interlaminar peeling and the tearing of fibers, JP 5-318218 A proposes a method of cutting an end surface of a fiber-reinforced plastic laminate by a cutter after heat curing, the fiber-reinforced plastic laminate comprising a carbon-fiber prepreg laminate and glass-fiber cloths provided on both surfaces, carbon fibers in surface layers of the carbon-fiber prepreg laminate being aligned in the same direction, and the cutter having a rake face inclining at an angle of 90-180° relative to the direction of the above carbon fibers.
To provide a fiber-reinforced composite member with a good cut surface, JP 2002-283101 A proposes a method of cutting an end surface of a rotating fiber-reinforced composite member by a tool, comprising vibrating the tool in a cutting direction, the movement of the tool relative to the fiber-reinforced composite member per one period of vibration being 2 times or less the diameter of reinforcing fibers.
However, the methods of JP 59-27827 B, JU 2-82461 A and JP 2002-283101 A need special tools, resulting in high cost. Also, the method of JP 5-318218 A is limited to a fiber-reinforced plastic laminate with a particular lamination structure, resulting in limited freedom of design.